\header {

  texidoc = "\\consists can take a scheme alist as arguments, which
  should be functions, which will be invoked as engraver functions."

}

\version "2.13.11"

\layout {
  \context {
    \Voice
    \consists
    #(list
      (cons 'initialize
       (lambda (trans)
	(display (list "initialize"
		  (ly:context-current-moment
		   (ly:translator-context trans)) "\n"))))
      (cons 'start-translation-timestep
       (lambda (trans)
	(display (list "start-trans"
		  (ly:context-current-moment
		   (ly:translator-context trans)) "\n"))))
      (cons 'listeners
       (list
	(cons 'rest-event (lambda (engraver event)
			   (let*
			    ((x (ly:engraver-make-grob engraver 'TextScript event)))
			    (display (list "caught event" event "\ncreate:\n" x "\n"))
			    (ly:grob-set-property! x 'text "hi"))
			   ))
       ))
      (cons 'acknowledgers
       (list
	(cons 'note-head-interface
	 (lambda (engraver grob source-engraver)
	  (display (list "saw head: " grob " coming from " source-engraver))
	  ))
	))
      (cons 'end-acknowledgers
       (list
	(cons 'beam-interface
	 (lambda (engraver grob source-engraver)
	  (display (list "saw end of beam: " grob " coming from " source-engraver))
	  ))
	))
      (cons 'process-music
       (lambda (trans)
	(display (list "process-music"
		  (ly:context-current-moment
		   (ly:translator-context trans)) "\n"))))
      (cons 'process-acknowledged
       (lambda (trans)
	(display (list "process-acknowledged"
		  (ly:context-current-moment
		   (ly:translator-context trans)) "\n"))))
      (cons 'stop-translation-timestep
       (lambda (trans)
	(display (list "stop-trans"
		  (ly:context-current-moment
		   (ly:translator-context trans)) "\n"))))
      (cons 'finalize
       (lambda (trans)
	(display (list "finalize"
		  (ly:context-current-moment
		   (ly:translator-context trans)) "\n"))))
    )

		}}


\relative c' {
  c8[ r c]
}